US 5,842,387 A · Knife blades having ultra-sharp cutting edges and methods of fabrication

Abstract

Knife blades having exceptionally sharp cutting edges are formed from wafers of monocrystalline silicon using known semiconductor processing technology. In one embodiment, an elongated ridge having a flat top covered by an etchant mask is etched to undercut the mask and to shape the ridge side walls to inwardly converge towards the ridge tip. The mask is removed and a sharp ridge apex is provided by a series of oxide forming and oxide stripping processes. Individual knife blades of silicon, each comprising a ridge having a sharp cutting edge, are shaped from the wafer. In another embodiment, the silicon wafer is etched entirely through between top and bottom surfaces to form a tapered etched wall intersecting the bottom wall at a highly acute edge. The edge is sharpened by the oxide forming and oxide stripping process to form a cutting edge in the completed blade. In both embodiments, various etch masks and etching procedures are used for providing blades of various shapes.

Claims10

Dependent claims

A method of forming a knife blade comprising the steps of:

providing a first etchant masking layer covering a first surface of a substrate and a second masking layer partially covering a second surface of said substrate oppositely disposed to said first surface, said second masking layer having a shape terminating in a first edge exposing a portion of said second surface, etching into said substrate through said exposed portion of said second surface for forming a depression in said substrate, said depression having a bottom surface and a side surface connected to said second surface along a line, changing the shape of said second masking layer so that said changed second masking layer terminates in a second edge spaced from said line for exposing said depression and another portion of said second surface extending between said line and said second edge, and etching into said substrate through said depression and said another portion exposed by said changed second masking layer for forming a continuous surface extending between said substrate first and second surfaces, said continuous surface forming an acute angle with said first surface.

Dependencies are inferred from the claim text.

Knife blades having ultra-sharp cutting edges and methods of fabrication

Life of this patent

Knife blades having ultra-sharp cutting edges and methods of fabrication

Life of this patent

Abstract

Claims10